Background: Tinnitus, as a common symptom, can jeopardize the sleep quality and brain function and even lead to hearing loss and cognitive decline in elderly patients. The co-occurring tinnitus and sleep disturbances can significantly affect the cognitive functions and quality of life, and even be implicated as a key contributing factor in the development of prodromal dementia. At present, very few non-pharmacological therapies are developed for managing these comorbidities in elderly patients. Focused low-intensity transcranial ultrasound stimulation (TUS) enables to stimulation the deep brain structures, such as hippocampus, with optimized focality and specific frequency.

Objectives: We aim to 1) investigate the safety, feasibility and efficacy of a 2-week focused low-intensity TUS on the severity of tinnitus and sleep disturbances in elderly patients; 2) determine the sample size of a full-scale randomized clinical trial of low-intensity TUS in patients with tinnitus; 3) evaluate the effects of low-intensity TUS on the severity of tinnitus, sleep quality and cognitive functions at 2, 4 and 6 weeks after the treatments.

Design: A 2-week randomized, double-blind, controlled clinical trial.

Methods: Chinese right-handed tinnitus patients with sleep disturbances (aged from 60 to 90 years) will be randomly assigned to a 2-week intervention of either low intensity TUS or sham TUS, with 7 participants per arm. Before intervention, T1-weighted magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI) data is used to construct individual realistic head model. Comprehensive assessments, including sleep quality, cognitive performance and quality of life will be conducted at baseline, 2nd week, 4th week and 6th week. Program adherence and adverse effects will be monitored throughout intervention.